Herbicides were developed during the 20th century to be used with conventional tillage for weed control. Conservation (or minimum) tillage subsequently evolved, which enabled less soil damage when used with herbicides.

Selection pressure, however, has resulted in weed species that have made adaptations for survival in conjunction with tillage.

The U.S. government has put several federal policies and programs in place that help determine the selection and implementation of crops and conservation programs in relation to herbicides and tillage. The authors of this paper discuss those programs with regard to

The disagreement among organizations, there being no simple solutions;

The need for collaboration among all parties; and

A case study of Palmer amaranth, “one of the most high-profile problems,” in Georgia cotton.

The balance between conservation tillage and herbicide-resistant (HR) weed management is the central issue addressed in the paper. As the authors state, “The fundamental conflict facing many producers with HR weed management issues today is the choice between using tillage or land stewardship practices that protect soil and water resources.”

A few of the paper’s conclusions include the following:

Soil conservation is threatened by HR weeds

Growers are including and/or intensifying tillage practices because of HR weeds

Education programs are needed to show how HR weeds can be managed without losing recent gains

More research is necessary regarding HR weed management and soil conservation goals

Task force authors are:

David Shaw, Chair, Mississippi State University

Stanley Culpepper, University of Georgia

Micheal Owen, Iowa State University

Andrew Price, National Soil Dynamics Laboratory

Robert Wilson, University of Nebraska

The full text of Issue Paper 49 may be accessed free of charge on the CAST website at www.cast-science.org, along with many of CAST’s other scientific publications. The paper also is available in hard copy for a shipping/handling fee. CAST is an international consortium of scientific and professional societies, companies, and nonprofit organizations. It assembles, interprets, and communicates credible science-based information regionally, nationally, and internationally to legislators, regulators, policymakers, the media, the private sector, and the public.